@type t() :: %LINE.Bot.MessagingApi.Model.FlexBubble{
  action: LINE.Bot.Model.Action.t() | nil,
  body: LINE.Bot.Model.FlexBox.t() | nil,
  direction: String.t() | nil,
  footer: LINE.Bot.Model.FlexBox.t() | nil,
  header: LINE.Bot.Model.FlexBox.t() | nil,
  hero: LINE.Bot.Model.FlexComponent.t() | nil,
  size: String.t() | nil,
  styles: LINE.Bot.Model.FlexBubbleStyles.t() | nil,
  type: String.t()
}